Hi.
This code in breada
if (blocks < (read_ahead[MAJOR(dev)] >> index))
blocks = read_ahead[MAJOR(dev)] >> index;
will increase number of block that are read ahead. However the code
doesn't check for end of device and so it can generate accesses beyond end
of device.
This is the patch (is there any better way to find number of blocks? what
if partitions had odd number of sectors?) The patch is for both 2.2 and
2.3.
Mikulas
--- linux/fs/buffer.c_ Tue Feb 29 00:29:18 2000
+++ linux/fs/buffer.c Tue Feb 29 01:11:07 2000
@@ -958,6 +958,15 @@
if (blocks > NBUF)
blocks = NBUF;
+ if (blk_size[MAJOR(dev)]) {
+ unsigned int dev_size;
+ if (index < 1) dev_size = blk_size[MAJOR(dev)][MINOR(dev)] >> (1 - index);
+ else dev_size = blk_size[MAJOR(dev)][MINOR(dev)] << (index - 1);
+ if (block + blocks > dev_size)
+ if (dev_size > block) blocks = dev_size - block;
+ else blocks = 1;
+ }
+
/* if (blocks) printk("breada (new) %d blocks\n",blocks); */
-
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